The culinary world often seems very faddish, as the food media and chefs strive to be innovative and fashionable. Usually these fads concern some obscure ingredient (fennel pollen is a hot item currently), or rediscovered style (look at the number of bistros in your neighborhood). But one stylish food today is that most historical and commonplace of foods, cheese.

Restaurants are wheeling out cheese carts with a myriad of choices - the restaurant Artisanal, in NYC lists 200 cheeses on their menu. A cheese steward follows, much as the wine list is followed by the sommelier. But while a lot of attention is paid to composing a suitable cheese course, or defining hundreds of different cheeses, little attention is paid to cooking with cheese.

To understand how to cook with cheese you need to know what happens when cheese is exposed to heat. Cheese is formed of water, fats, and proteins. Beyond 140 degrees F, or after lengthy exposure to any heat, the protein coagulates (joins together) and separates from the fat and water, producing a tough, stringy mass. After coagulating, no amount of heat or stirring will smooth out the cheese, and the dish can not be fixed.

Therefore, the best approach to working with cheese is to minimize the exposure to heat, both as to temperature and time, by whichever of the following is appropriate:

ü       Add the cheese at the end of the cooking time and off the heat.

ü       Microwave any dish with cheese at no more than 70% power.

ü       To brown cheese, put the dish 4 - 6 inches under the broiler just until melted.

ü       Add cheese toppings during the last 5 - 10 minutes of cooking, and keep the oven between 325 and 375 degrees.

ü       Grate, crumble, or shred the cheese before adding; do not add cheese in large chunks or slices that take too long to melt. To grate or shred soft cheeses more easily, put the cheese in the freezer for a few minutes.

When appraising how a specific type of cheese will react to heat, first look at fat content. A lower fat cheese, such as cottage cheese, ricotta, or feta has a higher proportion of protein and will not stand heat as well as a higher fat cheese. At the extreme, diet or non-fat cheese versions of naturally higher fat cheeses (cheddar, brick, or Monterey Jack) will never melt.

Higher fat cheeses like whole milk mozzarella or provolone will melt better and blend more easily in sauces that have other fats and liquid components as the different fats and liquids bond well. Therefore, higher fat cheeses are a good choice for baked dishes and sauces where you want the cheese to be well blended with the rest of the food.

Texture of a cheese has little to do with fat content. Soft, firm or hard cheeses can be either low or high in fat content. Firmer cheeses are those that have been aged; some cheeses like Monterey Jack or Cheddar can be found in a variety of textures depending on their age.

If the dish you are preparing requires high temperature - such as gratins that will go under the high heat of a broiler - and you want a cheese that will brown and crust; the harder cheeses will tolerate direct heat better than soft cheeses. The protein in the very hard or grating cheeses, (parmesan, pecorino) has been broken down into tiny fragments. These fragments have a harder time finding each other. Also, grated cheese disperses evenly, and is a good choice for a sauce, custard, or soufflé.

Regardless of the cheese type, if you are concerned about a cheese melting (and staying melted), certain additives will interfere with coagulation. Wine in a cheese fondue provides both taste and protection as alcohol lowers the boiling point of liquid, permitting the fondue to be kept at a lower temperature. Starch added to a sauce (such as the flour in a white sauce) keeps the mixture stable as the starch grains hold the cheese particles in suspension. Lemon juice also helps prevent coagulation.

Here are a couple of other tips about cooking with cheese:

1.       Cooking mellows the taste of cheese, so choose a stronger cheese for a cooked dish than you would like if you were to eat the cheese out of hand. Sharp cheddar is more effective in a sauce than mild cheddar; other examples include gouda, blue cheeses, provolone, or gruyere vs. American Swiss.

2.        Freezing cheese to use later in a cooked dish can save you from throwing out excess cheese. Cows milk cheeses do not freeze well as the cheese gets dry and crumbly. However, dry and crumbly cheese is fine for cooking, so if you have too much cheese to eat, freeze grated or shredded cheese in a tightly sealed bag. Goat's milk and sheep's milk cheeses do freeze well for all purposes.

3.        Almost all recipes specify how much cheese to add by using a dry cup measurement, (1/2 cup, etc.) Cheese, however, is sold by weight. The following is a guideline as to how much to buy:

ü       4 ounces of natural cheese = 1 cup shredded

ü       4 ounces of bleu cheese or feta cheese = 1 cup crumbled

ü       3 ounces of grating cheese (Parmesan, etc.) = 1 cup grated

Finally, a note about processed or American cheese, which is the easiest cheese to melt. Processed cheese legally needs only to be 51% actual cheese by weight. The cheese component is a blend of cheeses, usually Cheddar, Swiss, or Brick. Salt and preservatives are also added. These additives, and the smaller amount of actual cheese protein, create a product that requires less heat to melt, so there is less danger of coagulation. You pay for this security, however, at the cost of an inferior cheese flavor. Unless you are looking for that distinctive American cheese taste, it's worth taking the effort to cook with natural cheese.